<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<style>
			* {
				box-sizing: border-box;
			}
			.parent {
				/* border: 5px solid #000; */
				background-color: #000000;
				/* 声明弹性容器 */
				display: flex;
			}
			.son1 {
				/* border: 5px solid #f00; */
				background-color: #f00;
				/* flex-basis: 0px; */
				/* flex-grow: 1; */
				flex: 1;
			}
			.son2 {
				/* border: 5px solid #0f0; */
				background-color: #0f0;
				/* flex-basis: 0px; */
				/* flex-grow: 1; */
				flex: 1;   /*等价于：  flex:  1  1  0%*/
			}
			.son3 {
				/* border: 5px solid #00f; */
				background-color: #00f;
				flex-basis: 400px;
				flex-grow: 0;
			}
		</style>
	</head>
	<body>
		<div class="parent">
			<div class="son1">11111</div>
			<div class="son2">2222222222222222222222222222222</div>
			<div class="son3">33333</div>
		</div>
	</body>
</html>
